package com.enbatis.mybatisplugs.toolkit;

import org.apache.commons.lang.text.StrTokenizer;

import javax.servlet.http.HttpServletRequest;
import java.util.regex.Pattern;

/**
 * 自定义访问对象工具类
 *
 * 获取对象的IP地址等信息
 * @author X-rapido
 *
 */
public class CusAccessObjectUtil {

    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址,
     *
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？
     * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。
     *
     * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130,
     * 192.168.1.100
     *
     * 用户真实IP为： 192.168.1.110
     *
     * @param request
     * @return
     */
    public static String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }




        public static final String _255 = "(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)";
        public static final Pattern pattern = Pattern.compile("^(?:" + _255 + "\\.){3}" + _255 + "$");

        public static String longToIpV4(long longIp) {
            int octet3 = (int) ((longIp >> 24) % 256);
            int octet2 = (int) ((longIp >> 16) % 256);
            int octet1 = (int) ((longIp >> 8) % 256);
            int octet0 = (int) ((longIp) % 256);
            return octet3 + "." + octet2 + "." + octet1 + "." + octet0;
        }

        public static long ipV4ToLong(String ip) {
            String[] octets = ip.split("\\.");
            return (Long.parseLong(octets[0]) << 24) + (Integer.parseInt(octets[1]) << 16)
                    + (Integer.parseInt(octets[2]) << 8) + Integer.parseInt(octets[3]);
        }

        public static boolean isIPv4Private(String ip) {
            long longIp = ipV4ToLong(ip);
            return (longIp >= ipV4ToLong("10.0.0.0") && longIp <= ipV4ToLong("10.255.255.255"))
                    || (longIp >= ipV4ToLong("172.16.0.0") && longIp <= ipV4ToLong("172.31.255.255"))
                    || longIp >= ipV4ToLong("192.168.0.0") && longIp <= ipV4ToLong("192.168.255.255");
        }

        public static boolean isIPv4Valid(String ip) {
            return pattern.matcher(ip).matches();
        }

        public static String getIpFromRequest(HttpServletRequest request) {
            String ip;
            boolean found = false;
            if ((ip = request.getHeader("x-forwarded-for")) != null) {
                StrTokenizer tokenizer = new StrTokenizer(ip, ",");
                while (tokenizer.hasNext()) {
                    ip = tokenizer.nextToken().trim();
                    if (isIPv4Valid(ip) && !isIPv4Private(ip)) {
                        found = true;
                        break;
                    }
                }
            }
            if (!found) {
                ip = request.getRemoteAddr();
            }
            return ip;
        }



}